Esophageal Cancer
The esophagus is the muscular passage that food and liquids use to reach the stomach. The two main types of esophageal cancer are squamous cell carcinoma
(which starts in the cells of the lining) and adenocarcinoma (which starts in the tissue that helps you swallow).
OVERVIEW
What is esophageal cancer?
The esophagus is a long, muscular tube that runs from the throat to the stomach. The esophagus is made up of several layers of muscle that contract to
help move food down the tube and into the stomach. A special muscle called the esophageal sphincter acts as a valve, opening to allow food and liquids to pass
from the esophagus into the stomach.
Esophageal cancer results when abnormal cells grow out of control in esophageal tissue. Eventually the cells form a mass called a tumor.
There are two main types of esophageal cancer:
- Squamous cell carcinoma:- begins in the cells (called squamous cells) that line the esophagus. This cancer usually
affects the upper and middle part of the esophagus.
- Adenocarcinoma:- develops in the tissue that produces mucus that aids in swallowing. It generally occurs in the lower part of the esophagus.
SYMPTOMS AND CAUSES
What causes esophageal cancer?
The exact cause of esophageal cancer is not known, but there are several risk factors for the disease. Risk factors for esophageal cancer include:
- Older age:- Esophageal cancer occurs more often in people older than 60 years than in those aged 60 or younger.
- Male gender:- Men are three times more likely to develop the disease than women.
- Ethnicity:- Squamous cell esophageal cancer happens more often in African Americans and Asians. Adenocarcinoma happens more often in whites.
- Tobacco use:- This includes smoking and using smokeless tobacco.
- Alcohol use:- Chronic and/or heavy use of alcohol increases the risk of esophageal cancer.
- Barrett’s esophagus and chronic acid reflux:- Barrett’s esophagus is a change in the cells at the lower end of the esophagus that
occurs from chronic untreated acid reflux. Even without Barrett’s esophagus, people with long-term heartburn have a higher risk of esophageal cancer.
- Human papilloma virus (HPV):- In areas of the world that have a high incidence of esophageal cancer (such as Asia and South Africa),
infection with HPV carries an increased risk for developing esophageal squamous cell cancer. HPV is a common virus that can cause tissue changes in the vocal
cords and mouth, and on the hands, feet and sex organs.
- Other disorders:- Other conditions have been linked to esophageal cancer. These include achalasia, an uncommon disease that causes
difficulty swallowing, and tylosis, a rare, inherited disorder in which excess skin grows on the palms of the hands and the soles of the feet.
- Occupational exposure to certain chemicals:- People exposed to dry cleaning solvents over long periods of time are at higher
risk for esophageal cancer.
- History of cancer:- People who have had cancer of the neck or head have a greater risk for esophageal cancer.
What are the symptoms of esophageal cancer?
Esophageal cancer may have no obvious symptoms in its early stages. The symptom people notice first is difficulty swallowing. As the tumor grows,
it narrows the opening of the esophagus, making swallowing difficult and/or painful. Other symptoms of esophageal cancer can include:
- Pain in the throat or back, behind the breastbone, or between the shoulder blades
- Vomiting or coughing up blood
- Heartburn
- Hoarseness or chronic cough
- Unintentional weight loss
DIAGNOSIS AND TESTS
How is esophageal cancer diagnosed?
The doctor will ask you about your medical history, including your current symptoms. After a physical examination, the doctor might order certain
tests that can help in diagnosing and assessing esophageal cancer.
- Barium swallow:- uses a special series of X-rays to visualize the esophagus. The patient drinks a liquid containing barium,
which makes the esophagus easier to see on the X-ray.
- Esophagoscopy:- is a procedure that allows the doctor to look at the inside of the esophagus using a thin, lighted tube
called an endoscope. For the test, the endoscope is passed through the mouth and down the throat into the esophagus while you are asleep. The
endoscopy can also be used to relieve obstruction. The doctor can insert a balloon to dilate an obstructed esophagus. Looking at the esophagus and
the upper part of the stomach is called an upper endoscopy.
- Biopsy:- During the esophagoscopy, the doctor may remove a small piece of tissue to examine under a microscope to see if there
are any cancer cells.
- Esophageal endoscopic ultrasound:- uses sound waves to create images of internal structures. In this procedure,
the ultrasound is performed through the esophagoscope.
- Computed tomography (CT):- is often used to evaluate the extent of the tumor spread to the chest and abdomen.
How is esophageal cancer classified?
Most cancers are grouped by stage, a description of the cancer that aids in planning treatment. The stage of a cancer is based on the location
and depth of the tumor; the involvement, if any, of the lymph nodes; and the degree that the cancer has spread, if at all, to other tissue and organs.
In addition to staging the cancer, tumors may also be graded. Grading is a way of rating a tumor based on how much its cells look and act
like normal cells. Tumor grading can also tell the doctor how fast the tumor is growing. Tumors with almost normal-looking cells that grow slowly are
called low-grade tumors. Tumors with very abnormal-looking cells that divide rapidly are called high-grade tumors. High-grade tumors are more likely to spread
than low-grade tumors.
MANAGEMENT AND TREATMENT
How is esophageal cancer treated?
The approach to treatment depends on the stage and grade of the cancer. Treatment options that may be used for esophageal cancer include:
- Surgery:- is the most common treatment for esophageal cancer. Surgery may be done to remove some or most of the esophagus,
as well as some tissue around it, in a procedure called esophagectomy. If the esophagus is removed, the doctor may reposition the stomach
(moving it up into the chest), or use a piece of intestine to preserve function. The doctor may also remove lymph nodes around the esophagus
and look at them under a microscope to see if they contain cancer. Surgery can cure cancer in some patients who have no spread of the tumor
beyond the esophagus. Unfortunately, less than 25 percent of esophageal cancers are discovered this early. Therefore, surgery is often offered to ease symptoms.
Esophageal cancer surgery often requires extended hospitalizations. Some surgeons are now doing the procedures using minimally invasive techniques.
Complications include: stomach emptying problems, narrowing where the surgery was performed and heartburn.
- Radiation therapy:- is a way of treating disease using radiation (high-energy rays) or radioactive substances. It is used to
kill or damage cancer cells, often by aiming a beam of radiation at the tumor. The radiation destroys the cancer cells by interfering with their
growth and division. Radiation can be used alone, before surgery to shrink tumors, or after surgery to kill any cancer cells that may remain. During
radiation treatments for esophageal cancer, a stent (small tube) is sometimes inserted into the esophagus to keep it open. This is called intraluminal
intubation and dilation.
Radiation therapy is mainly used as part of a larger treatment regimen to relieve difficulty swallowing.
- Chemotherapy:- uses medicines to kill or stop the growth of cancer cells. Some chemotherapy drugs are taken as pills and some are placed
directly into the bloodstream through a vein (intravenous). Chemotherapy drugs travel through the bloodstream and can kill cells throughout the body.
For esophageal cancer, chemotherapy is sometimes used before surgery to help shrink the tumor.
Chemotherapy can be given to control symptoms (palliative), before surgery to shrink the tumor, or can be used in conjunction with radiation.
- Endoscopic submucosal dissection (EDS) or endoscopic mucosal resection (EMR):- are procedures to treat early tumors that are small. The tumors
may be removed endoscopically without having to remove the esophagus.
- Endoscopic laser therapy:- may be used to treat more advanced tumors that may cause a blockage in the esophagus. As part of palliative therapy,
lasers can be used to cut a hole in the blockage to improve swallowing and allow the patient to eat.
- Photodynamic therapy (PDT):- uses photoactive drugs (drugs activated by non-thermal light) that are absorbed by cancer cells,
thus destroying the cancer cells. This treatment may be used to help ease the symptoms of esophageal cancer, particularly difficulty swallowing.
PREVENTION
Can esophageal cancer be prevented?
Although esophageal cancer cannot be prevented, controlling the risk factors, such as tobacco and alcohol use, may help reduce the risk of developing the disease.
A study has indicated that people with Barrett’s esophagus who are treated with radiofrequency ablation are less likely to develop esophageal cancer.
OUTLOOK / PROGNOSIS
What is the outlook for people with esophageal cancer?
The chance of recovery depends on the stage of the cancer and the person’s general health. If caught early, esophageal cancer can often be successfully treated.
Unfortunately, esophageal cancer usually is not discovered until it has progressed to an advanced stage, when treatment is less successful.